In locomotive repair shops, the only means of safely replacing the engine accessories of General Motors locomotives is twofold. The first method is by means of a tramrail that is inserted through the openings of the carbody access doors, suspended from the carbody, and used in conjunction with come-alongs to hoist the accessories and transfer them laterally to the side of the locomotive, where they are lowered onto transport wagons. The other means of removal is by removing the locomotive carbody hatch. An undesirable third method, and one in common use on some rail lines, is removal by hand. Since these accessories weigh from 65 to 275 lbs., it is clear that this means of removal is unsafe.
The most practical means of removal, with the tramrail and come-along, is sometimes very difficult to endeaver, because often the tramrail can not be secured to the locomotive carbody without first welding an attachment bracket to the carbody. Then, once the tramrail is in place, the area left to the mechanic to work in is reduced, and as a result he is put in a bind when removing the accessories and operating his come-along. Also, once the tramrail is secured in place over the accessories, it has only lateral flexibility, and all forward-reverse movement of the accessories necessary for removing them from their engine flanges must be made forcibly and away from the center of gravity of the tramrail. Further, the mechanical come-along is slow in its function of raising and lowering accessories, and at the same time requires an undue amount of arm action, with the ratchet arm of the come-along usually being restricted or interfered with by other parts in the small confines of what is known in rail shops as the accessories room; i.e. the area at the front of the engine where the engine small parts are located. Because of the closeness of these rooms, electric and hydraulic lifts suspended from the tramrail are unacceptable due to the danger that error of operation may trap or injure the mechanic. Also, the danger of a hydraulic or electric line being cut is apparent.
Two existing inventions address the special needs for removing certain larger locomotive parts, but fail to be of assistance in the removal of the smaller engine accessories.
The first example is that of James, with his Power Assembly Removal Tool, U.S. Pat. No. 3,843,85. This is a hydraulics actuated lifting device designed for removing power assemblies from locomotives without removing the carbody hatch. Although this device satisfies the need for assembly removal, it can not be used as a universal engine accessories remover because of its design and because it has no means of attachment to engine accessories. Further, it can not be modified to attach to engine accessories without rendering it useless for pulling power assemblies.
The second example is that of Jones, with his Oil Cooler Puller Having Only One Suspension Point, U.S. Pat. No. 4,773,688. Again, the inventor addresses the needs of removing a particular large part on the locomotive, in this case an oil cooler; and again, the device satsifies its claims, but can not be used as a universal engine accessories remover because it has no means of attachment to engine small parts, nor could it be modified to be a universal accessories remover without rendering it useless for pulling oil coolers.
In both of the above cases, it can be seen that to attempt modification of the lower arms to the use of universal engine accessories removers would render the inventions useless in their intent and violate the letter of their claims.